1. Field of the Invention
The present invention relates to an adjustable ratchet retractor support apparatus useful, for example, in abdominal, thoracic and orthopedic surgery.
2. The Prior Art
In many surgical operations it is customary to employ a table-fixed retraction apparatus in which a frame or mounting ring rests over the patient surrounding the surgical opening, and a number of retractors may be movably attached to the frame and flexibly positioned, with various clamping or positioning mechanisms, to reach into the surgical opening and retract surrounding or obstructing tissue or organs, or to stabilize or position tissue or organs that are being worked on. In general, such retractors may include a blade or spoon-like member, or various gripping members, that each extend from an elongated handle or stem, and the stem moves within a clamping mechanism that mounts on the mounting ring and locks the blade or gripping member in a selected position. The clamping mechanism may itself have a mechanical structure allowing one or more additional degrees of movement in rotation or displacement, so that both the position and orientation of the blade may be quickly set and locked. Various common machine elements such as swivel ball mounts, arcuate rack or tilt mounts, ratchet or rack adjustment and locking mechanisms, or screw clamps may be incorporated in the clamping structures to provide assemblies that are moved by hand into the desired position and locked.
By way of example, one commercially useful system is shown in the various patents of John R. Bookwalter et al., such as U.S. Pat. Nos. 4,424,724; 4,254,763; 4,421,108; 5,375,481; and 5,520,608. This system is made and marketed by Codman. In the Bookwalter system, the frame element is a is a flat ring with regular notches. The ring is held by a post that clamps to the side rail of the operating table, so the ring is suspended in a plane above the surgical site. The plane of the ring sets one constraint on the movement of the retractor units, and allows the various retractor clamp assemblies to move into position and lock with a sliding movement that is conveniently set with one hand. This system is discussed in Bookwalter et al. U.S. Pat. No. 6,241,659.
Other surgical retractor systems are shown in LeVahn et al. U.S. Pat. No. 4,949,707; O""Connor et al. U.S. Pat. No. 1,919,120; Giglio et al. U.S. Pat. No. 5,520,610; Morin U.S. Pat. No. 1,963,173; Darnell U.S. Pat. No. 4,434,791; Dinkler et al. U.S. Pat. No. 5,529,358; and Koros et al. U.S. Pat. No. 5,795,291.
Although a number of retractor systems are known, there is still a need for a retractor support apparatus with the ability to open or close either side of a two-piece ring independently using a quick-release ratchet mechanism that allows rapid positioning of the ring to provide increased exposure to the operative incision without having to make other adjustments.
An adjustable ratchet retractor support apparatus is provided. In one aspect, the apparatus includes a rotatable locking mount, first and second rotatable pivot members, first and second curved arm members, and first and second rotatable clamps.
The locking mount has first and second surfaces and an axis of rotation perpendicular to these surfaces.
The pivot members are disposed respectively on the first and second surfaces of the locking mount for rotation around the axis of rotation. Each of the pivot members include ratchet teeth.
The arm members are mounted respectively on and associated respectively with the first and second pivot members. Each of the arm members is rotatable about a respective axis of rotation perpendicular to the axis of rotation of the locking mount. A ratchet pawl is mounted on each arm member for engagement with the ratchet teeth of the associated pivot member.
The clamps are disposed respectively on the first and second pivot members for restraining rotation of the pivot members.
In another aspect, the apparatus includes a connector including first and second sets of ratchet teeth and first and second curved arm members mounted to the connector. Each of the arm members is rotatable around a respective axis of rotation perpendicular to the connector. Each arm member also has mounted thereon a respective ratchet pawl for engagement with a corresponding one of the sets of ratchet teeth.